1. Field of the Invention
The present invention relates to a bar-code reading apparatus that reads a bar-code label is attached to a magnetic tape cartridge (hereinafter, simply “cartridge”), etc. and, particularly, relates to a bar-code reading apparatus, bar-code reading method, bar-code reading program, and library apparatus that read a bar-code with reflected light from the bar-code label.
2. Description of the Related Art
On a cartridge that stores a magnetic tape used for writing or reading various data, a bar-code label used for a volume identifier. A library apparatus stores the cartridge in a cell and is provided with a magnetic tape drive apparatus that reads/writes data from/to the magnetic tape and a robot mechanism unit that carries the cartridge between the cell and the magnetic tape drive apparatus as well as a controller that controls functioning units such as the robot mechanism unit and the magnetic tape drive apparatus, and the robot mechanism unit is provided with a bar-code reader that reads the bar-code label from the cartridge. Volume information read by the bar-code reader is used for identifying the cartridge, etc. The known bar-code reader includes a laser type using a polygon mirror, a laser source, etc. and a CCD type combining a lens and a CCD (Charged Coupled Device) device.
With regard to such bar-code reading, in disclosure of Japanese Patent Application Laid-Open Publication No. 1991-171248 (right column of page 1, from line 12, etc.), a light emitting device and a light receiving device are provided in a case of a card-type electronic device and a bar-code is read by illuminating a bar-code with light of the light emitting device and receiving the reflected light with the light receiving device. In disclosure of Japanese Patent Application Laid-Open Publication No. 1997-91930 (paragraph No. 0021, FIG. 3, etc.), a library apparatus reads a bar-code with reflected light from a bar-code label of a recording medium in a cell.
By the way, a bar-code reader using a polygon mirror, a lens, a CCD, etc. increases a manufacturing cost and when the entire bar-code label is illuminated by a laser beam, a distance between a laser source and the bar-code label is elongated and a bar-code reader cannot be miniaturized because of characteristics of a half field angle of the lens, etc. Such a bar-code reader cannot be provided in the robot mechanism unit carrying the cartridge, and when a proportion of an area occupied by the bar-code reader is increased in the library apparatus, a moving range of the robot mechanism unit and installation of the cells are hampered. In the case of a small library apparatus, a storage efficiency of the cartridges may be reduced.
For example, as shown in FIGS. 15A and 15B, a library apparatus 100 is provided with a bar-code reader 108 at a hand unit 106 of a carrier robot 104 for a cartridge 102. Grippers 110, 112 for gripping the cartridge 102 are provided on the sides of the hand unit 106. A column 114 is a group of a plurality of cells 116 housing the cartridges 102. The carrier robot 104 moves the hand unit 106 vertically along the column 114, positions the bar-code reader 108 at a bar-code label 118 of the reading-target cartridge 102, and reads a bar-code from the bar-code label.
In this case, the bar-code reader 108 is constituted by a CCD 120, a lens 122, etc. and has a relatively large volume on the top surface of the hand unit 106.
In such a bar-code reader 108, the reading position is different from the gripping position of the grippers 110, 112 of the hand unit 106 and, in the example of FIG. 15B, a difference of a height Δh is generated. If the bar-code reader 108 is used, after the volume registration by reading a bar-code, the position of the hand unit 106 must be changed to the cartridge 102 that should be gripped to perform a cartridge gripping step in addition to the reading. That is, when putting the cartridge 102 into the library apparatus 100, two steps are needed, which are a step for reading the bar-code label 118 and a step carrying the cartridge 102 to the cell 116. Therefore, it is problematic that an inputting process of the cartridge 102 to the library apparatus 100 takes time.
Japanese Patent Application Laid-Open Publication Nos. 1991-171248 and 1997-91930 do not disclose or indicate such a problem and do not include a configuration or concept for solving the problem.